1. Field of the Invention
The present invention relates to a delivery apparatus in which signatures--each of which is cut and folded at a folding section of a folding machine of a rotary press and is received by a delivery fan--are placed on a transport conveyer disposed under the delivery fan such that the signatures overlap each other at a constant pitch and are delivered to the outside of the folding machine through operation of the transport conveyer, and more particularly to a signature-delivery-pitch regulating apparatus capable of causing a grip mechanism to grip each of signatures received by the delivery fan, while the signature is rotated and transported by the delivery fan, and capable of subsequently causing the grip mechanism to release the signature on the transport conveyer such that signatures are aligned on the transport conveyer at a constant pitch.
2. Description of the Related Art
Japanese Utility Model Registration No. 3032498 discloses an example of a signature-delivery-pitch regulating apparatus for a delivery apparatus of a folding machine, in which a grip mechanism grips each of signatures received by the delivery fan, while the signature is rotated and transported by the delivery fan, and releases the signature on the transport conveyer such that signatures are aligned on the transport conveyer at a constant pitch.
The conventional apparatus includes an endless chain that can be displaced from the inside of a rotary region of the delivery fan to the outside thereof, and a grip mechanism for gripping a signature is provided on each chain link of the endless chain. The grip mechanism grips a signature received by the delivery fan, pushes the signature out of the delivery fan while maintaining the gripped state, and releases the pushed-out signature onto the transport conveyer.
The grip mechanism provided on each chain link of the endless chain is composed of a first grip member and a second grip member. The first grip member is formed by the forward-side end portion of the chain link with respect to the direction of displacement of the chain. Specifically, the forward-side end portion of the chain link is bent perpendicularly to form the first grip member. The second grip member is swingably supported by a support shaft disposed at a central portion of the chain link in parallel with chain-link connection pins. The second grip member has at its one end a portion that faces the first grip member. Therefore, through swing movement of the second grip member, the opposed portion of the second grip member comes into contact with and separates from the first grip member.
Further, the second grip member is urged by means of a torsion coil spring in such a direction that the opposed portion of the second grip member separates from the first grip member in order to open the grip mechanism.
The other end of the second grip member is projected to the side of the chain link opposite the side to which the first grip member extends. The projected portion of the second grip member serves as an operation portion for bringing the opposed portion of the second grip member into contact with the first grip member against the force of the torsion coil spring to thereby close the grip mechanism.
Further, a stationary cam is provided. This stationary cam interferes with the operation portion of the second member, so that the grip mechanism is closed in a predetermined section while the endless chain travels. When the stationary cam interferes with the operation portion of the second grip member, the locus of the endless chain may expand outward due to the force of the torsion coil spring, resulting in incomplete closure of the grip mechanism. Therefore, a chain guide is provided in order to suppress the expansion of the locus of the endless chain.
The signature-delivery-pitch regulating apparatus disclosed in Japanese Utility Model Registration No. 3032498 has the following drawbacks to be solved.
In the apparatus, since the grip mechanism is composed of a first grip member, which is constituted by a perpendicularly-bent-portion of a chain link, and a second grip member attached to the chain link, the depth of the grip mechanism cannot be increased. Therefore, the grip mechanism can grip each signature over only a short distance, so that the grip mechanism tends to drop the gripped signature. Especially, when the grip mechanism grips a thick signature, the possibility of dropping the signature increases.
In the apparatus, as the delivery fan rotates, a signature enters the grip mechanism in a direction substantially parallel to the first grip member. The tip end of the entered signature is received and stopped by the outer circumferential edge of the chain link in a state in which the signature hits the outer circumferential edge at a substantially right angle. Therefore, after hitting, the signature is driven back, resulting in a further decreased grip distance and incomplete gripping.
Therefore, the above-described conventional apparatus lacks reliability in regulating signature delivery pitch.
Further, in the conventional apparatus, the grip mechanism is normally brought into an opened state by the torsion coil spring, and when the grip mechanism is to be closed, the operation portion of the second grip member is caused to interfere with the stationary cam to thereby swing against the force of the torsion coil spring, so that the portion of the second grip member facing the first grip member comes into contact with the first grip member. Therefore, breakage of the torsion coil spring and wear of the support portion of the second grip member tend to occur easily, resulting in improper operation.
Further, in order to functionally operate the grip mechanism, the stationary cam--which forcibly close the second grip member against the force of the torsion coil spring--must be accurately provided at a predetermined position. Further, since the state of interference between the stationary cam and the second grip member must be maintained constant, the entire apparatus, including the grip mechanism, becomes complex and must have a high degree of accuracy.
In addition, while the stationary cam interferes with the operation portion of the second grip member, the two members come into rubbing contact with each other with a strong force, so that at least one of the members wears. Therefore, the worn member must be replaced with a new one at regular intervals in order to maintain the performance of the apparatus.
Accordingly, the above-described conventional apparatus requires a large number of steps in machining and assembly, as well as cumbersome maintenance and adjustment. In addition, manufacturing cost and running cost are both very high, partly due to the complicated shape of the chain links.